Fluid distribution material for absorbent articles

ABSTRACT

A fluid distribution material for use in an absorbent article includes a formed film layer having a user-facing side and a garment-facing side opposite the user-facing side. The formed film layer includes a plurality of apertured protuberances arranged in a pattern having 10 to 40 protuberances per linear inch. Each of the protuberances includes a continuous sidewall extending from the user-facing side. The garment-facing side has a plurality of apertures aligned with the plurality of apertured protuberances and land areas in between the apertures. A nonwoven layer is laminated to the garment-facing side of the formed film layer. The nonwoven layer includes a plurality of continuous fibers extending across the land areas and the plurality of apertures of the formed film layer and attached to the land areas at bond sites. The fluid distribution material has a compressibility of less than 10% between pressures of 0.21 psi and 0.60 psi.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation of U.S. patent application Ser. No. 16/285,611,filed on Feb. 26, 2019, which is a Continuation of U.S. patentapplication Ser. No. 15/989,852, filed on May 25, 2018, and issued asU.S. Pat. No. 10,258,517 on Apr. 16, 2019, the entire contents of bothof which are incorporated herein by reference.

FIELD

The present invention is directed to a fluid distribution material thatmay be used in absorbent articles, as well as absorbent articles thatinclude the fluid distribution material.

BACKGROUND

A variety of well-known absorbent articles are configured to absorb bodyfluids. Examples of such absorbent articles include, but are not limitedto, feminine hygiene products, such as sanitary napkins, baby diapers,adult incontinence products, and bandages. A typical absorbent articleis generally constructed with a fluid permeable user-facing topsheet,which may be a three dimensional apertured polymer film or a nonwovenweb or a film/nonwoven laminate, an absorbent core and a fluidimpermeable garment or outwardly-facing backsheet, which may be a solidpolymer film, for example.

A potential problem associated with absorbent articles may be theperceived lack of dryness of the user-facing topsheet of the absorbentarticle. Generally, the drier the skin feels that is contactingtopsheet, the more comfortable the absorbent article. In many instances,surface dryness of the topsheet may be correlated to fluid strikethroughefficiency. If the layer(s) beneath the topsheet are inefficient infully pulling the fluid out of the topsheet, residual wetness canremain. Moreover, wetness may reoccur and contribute to residual wetnessif the fluid is allowed to move from the layer(s) beneath the topsheetand back through the topsheet when the absorbent article is subjected topressure, which is a typical condition when the article is being worn bya user.

One or more additional layers may be added to the absorbent article inbetween the topsheet and absorbent core to improve fluid acquisition outof the topsheet and/or fluid distribution across the absorbent core sothat the fluid may be pulled through and out of the topsheet and intothe absorbent core more quickly and/or more completely. The additionallayer may be in the form of a nonwoven material, such as the liquidmanagement layer described in U.S. Pat. No. 8,426,671 (incorporatedherein by reference), or may be in the form of a three dimensionalapertured film, such as the acquisition distribution layer described inU.S. Pat. No. 7,378,568 (incorporated herein by reference) or theacquisition/distribution layer described in U.S. Patent ApplicationPublication No. 2005/0267429 (incorporated herein by reference), forexample. However, such an additional layer adds cost to the finalarticle and may also increase the thickness or bulkiness and/orstiffness of the article. Efforts to minimize the amount of materialthat is used in an additional layer by, for example, downgauging,particularly for a film, may be challenging because downgauging mayreduce the modulus of the material and negatively impact the ability toincorporate the layer into the final absorbent article during conversionprocesses.

It is desirable to provide a fluid distribution material that reducesresidual wetness, even after the absorbent article is subjected topressure, and has a modulus sufficient to allow the fluid distributionmaterial to be converted into an absorbent article.

SUMMARY

According to one embodiment, the present invention encompasses a fluiddistribution material for use in an absorbent article. The fluiddistribution material includes a formed film layer having a user-facingside and a garment-facing side opposite the user-facing side. The formedfilm layer includes a plurality of apertured protuberances arranged in apattern having 10 to 40 protuberances per linear inch. Each of theprotuberances includes a continuous sidewall extending from theuser-facing side. The garment-facing side has a plurality of aperturesaligned with the plurality of apertured protuberances and land areas inbetween the apertures. A nonwoven layer is laminated to thegarment-facing side of the formed film layer. The nonwoven layerincludes a plurality of continuous fibers extending across the landareas and the plurality of apertures of the formed film layer andattached to the land areas at bond sites. The fluid distributionmaterial has a compressibility of less than 10% between pressures of0.21 psi and 0.60 psi.

With respect to the fluid distribution material, the formed film layermay have a basis weight of between about 10 gsm and about 25 gsm.

Also with respect to the fluid distribution material, the nonwoven layermay have a basis weight of between about 10 gsm and about 15 gsm.

Still further with respect to the fluid distribution material, theplurality of continuous fibers of the nonwoven layer may be embeddedinto the land areas of the formed film layer at the bond sites.

In an embodiment of the fluid distribution materials, the nonwoven layermay include a spunbond nonwoven.

The present invention also provides a fluid management system for use inan absorbent article. The fluid management system includes a fluiddistribution material. The fluid distribution material includes a formedfilm layer having a user-facing side and a garment-facing side oppositethe user-facing side. The formed film layer includes a plurality ofapertured protuberances arranged in a pattern having 10 to 40protuberances per linear inch. Each of the protuberances includes acontinuous sidewall extending from the user-facing side. Thegarment-facing side has a plurality of apertures aligned with theplurality of apertured protuberances and land areas in between theapertures. A nonwoven layer is laminated to the garment-facing side ofthe formed film layer. The nonwoven layer includes a plurality ofcontinuous fibers extending across the land areas and the plurality ofapertures of the formed film layer and attached to the land areas atbond sites. The fluid distribution material has a compressibility ofless than 10% between pressures of 0.21 psi and 0.60 psi. In addition,the fluid management system includes a topsheet attached to the fluiddistribution material, where the user-facing side of the formed filmlayer faces the topsheet.

With respect to the fluid management system, the formed film layer mayhave a basis weight of between about 10 gsm and about 25 gsm.

Also with respect to the fluid management system, the nonwoven layer mayhave a basis weight of between about 10 gsm and about 15 gsm.

Still further with respect to the fluid management system, the pluralityof continuous fibers of the nonwoven layer may be embedded into the landareas of the formed film layer at the bond sites.

In another contemplated embodiment of the fluid management system, thetopsheet includes an apertured formed film.

The fluid management system also may have a topsheet that is a nonwovenweb.

In a contemplated alternative embodiment, the fluid management systemmay include a topsheet that is a laminate.

The present invention also provides an absorbent article that includes afluid distribution material. The fluid distribution material iscontemplated to include a formed film layer having a user-facing sideand a garment-facing side opposite the user-facing side. The formed filmlayer includes a plurality of apertured protuberances arranged in apattern having 10 to 40 protuberances per linear inch. Each of theprotuberances includes a continuous sidewall extending from theuser-facing side. The garment-facing side has a plurality of aperturesaligned with the plurality of apertured protuberances and land areas inbetween the apertures. A nonwoven layer is laminated to thegarment-facing side of the formed film layer. The nonwoven layerincludes a plurality of continuous fibers extending across the landareas and the plurality of apertures of the formed film layer andattached to the land areas at bond sites. The fluid distributionmaterial has a compressibility of less than 10% between pressures of0.21 psi and 0.60 psi. The absorbent article also includes a backsheetand an absorbent material in between the fluid distribution material andthe backsheet.

For the absorbent article, the formed film layer may have a basis weightof between about 10 gsm and about 25 gsm.

Also for the absorbent article, the nonwoven layer may have a basisweight of between about 10 gsm and about 15 gsm.

Still further for the absorbent article, the plurality of continuousfibers of the nonwoven layer may be embedded into the land areas of theformed film layer at the bond sites.

In an embodiment, the absorbent article may include a topsheet.

Where the absorbent article includes a topsheet, the topsheet may be anapertured formed film.

Alternative, the topsheet may be a nonwoven web.

Still further, the topsheet may be a laminate.

These and other aspects, features, and characteristics of the presentinvention, as well as the methods of operation and functions of therelated elements of structure and the combination of parts and economiesof manufacture, will become more apparent upon consideration of thefollowing description and the appended claims with reference to theaccompanying drawings, all of which form a part of this specification.It is to be expressly understood, however, that the drawings are for thepurpose of illustration and description only and are not intended as adefinition of the limits of the invention. As used in the specificationand in the claims, the singular form of “a”, “an”, and “the” includeplural referents unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

The components of the following figures are illustrated to emphasize thegeneral principles of the present disclosure and are not necessarilydrawn to scale. Reference characters designating correspondingcomponents are repeated as necessary throughout the figures for the sakeof consistency and clarity.

FIG. 1 is a schematic representation of an absorbent article inaccordance with embodiments of the invention;

FIG. 2 is a schematic enlarged cross-sectional side view of a portion ofa fluid distribution material of the absorbent article of FIG. 1 inaccordance with embodiments of the invention;

FIG. 3 is an enlarged photograph of a view of one side of an embodimentof the fluid distribution material of FIG. 2;

FIG. 4 is an enlarged photograph of a portion of the fluid distributionmaterial of FIG. 3;

FIG. 5 is an enlarged photograph of a partial cross-sectional side viewof the fluid distribution material of FIGS. 3 and 4;

FIG. 6 is an enlarged photograph of a view of one side of an embodimentof the fluid distribution material of FIG. 2;

FIG. 7 is an enlarged photograph of a portion of the fluid distributionmaterial of FIG. 6;

FIG. 8 is an enlarged photograph of a partial cross-sectional side viewof the fluid distribution material of FIGS. 6 and 7;

FIG. 9 is a schematic representation of an apparatus for manufacturingthe fluid distribution material in accordance with embodiments of theinvention;

FIG. 10 is a schematic enlarged cross-sectional side view of the portionof the fluid distribution material of FIG. 2 with an insult beingapplied to the fluid distribution material from above;

FIG. 11 is a schematic enlarged cross-sectional side view of the portionof the fluid distribution material and insult of FIG. 10 with the insultbeing handled by the fluid distribution material;

FIG. 12 is a schematic enlarged cross-sectional side view of the portionof the fluid distribution material and insult of FIGS. 10 and 11 withthe insult being further handled by the fluid distribution material;

FIG. 13 is a schematic enlarged cross-sectional side view of the portionof the fluid distribution material and insult of FIGS. 10, 11 and 12after the insult has passed through the fluid distribution material andinto an underlying material;

FIG. 14 is a plot of strikethrough testing results for embodiments ofthe invention and comparison samples;

FIG. 15 is a plot of rewet testing results for embodiments of theinvention and comparison samples;

FIG. 16 is a plot of compressibility as a function of applied pressurefor an embodiment of the fluid distribution material and a comparisonsample;

FIG. 17 is a plot of compressibility as a function of applied pressurefor an embodiment of the fluid distribution material and a comparisonsample;

FIG. 18 is a plot of compressibility as a function of applied pressurefor an embodiment of the fluid distribution material and a comparisonsample; and

FIG. 19 is a plot of compressibility as a function of applied pressurefor an embodiment of the fluid distribution material and a comparisonsample.

DETAILED DESCRIPTION

Various embodiments of the present invention will now be highlighted.The discussion of any one embodiment is not intended to limit the scopeof the present invention. To the contrary, aspects of the embodimentsare intended to emphasize the breadth of the invention, whetherencompassed by the claims or not. Furthermore, any and all variations ofthe embodiments, now known or developed in the future, also are intendedto fall within the scope of the invention.

Glossary

As used herein, the expression “absorbent articles” and “absorptivedevices” denote articles that absorb and contain body fluids and otherbody exudates. More specifically, an absorbent article/absorptive deviceincludes garments that are placed against or in proximity to the body ofa wearer to absorb and contain the various exudates discharged from abody. Non-limiting examples of absorbent articles include, but are notlimited to feminine hygiene products, baby diapers, adult incontinenceproducts, and bandages.

Throughout this description, the term “web” refers to a material capableof being wound into a roll. Webs can be film webs, nonwoven webs,laminate webs, apertured laminate webs, etc. The face of a web refers toone of its two dimensional surfaces, as opposed to one of its edges.

The term “composite web” or “composite material” refers to a web thatcomprises two or more separate webs that are attached to each other in aface to face relationship. The attachment can be through the edges ofthe component webs, although the component webs lie in a face to facerelationship with each other, or the attachment can be at particularspot locations across the component webs, or the attachment can becontinuous.

The term “film” or “polymer film” in this description refers to a webmade by extruding a molten curtain or sheet of thermoplastic polymericmaterial by a cast or blown extrusion process and then cooling the sheetto form a solid polymeric web. Films can be monolayer films, coextrudedfilms, coated films, and composite films.

“Coated films” are films comprising a monolayer or coextruded film thatare subsequently coated (for example, extrusion coated, impressioncoated, printed, or the like) with a thin layer of the same or differentmaterial to which it is bonded.

“Composite films” are films comprising more than one film where the atleast two films are combined in a bonding process. Bonding processes mayincorporate adhesive layers between the film layers.

Throughout this description, the expression “apertured films” denotesfilms that have a plurality of holes that extend from a first surface ofthe film to a second surface of the film.

A “two-dimensional apertured film” is a film in which nothree-dimensional structure exists in the holes, which then connect thesecond surface of a flat film to the first surface of the film.

A “formed film” or a “three-dimensional film” is a film withprotuberances, protrusions, or extended cells extending from at leastone side thereof, and an “apertured formed film” or a “three-dimensionalapertured film” is a film in which a three-dimensional structure existsin the apertures (e.g., the apertures have a depth that is thicker thanthe thickness of the film), or the protuberances or protrusions orextended cells have apertures therethrough.

The term “protuberance” as used herein refers to a three-dimensionalmember comprising an apertured base portion located in the plane of thefirst surface of the film and a sidewall portion extending generally inthe direction of the second surface of the film. Each base portion hasan associated sidewall portion. Sidewall portions terminate in “ends”located in the plane of the second surface of the film. The ends of theprotuberances may be apertured or unapertured.

“Apertured protuberance” as used herein refers to a protuberance thathas an aperture at its base portion or proximal end in the plane of thesecond surface, as well as its distal or protubered end. The aperturesin the base portions of the protuberances, also called “primaryapertures,” may be in the shape of polygons, for example squares,hexagons, pentagons, ellipses, circles, ovals, or slots, in a regulatedor random pattern. In an embodiment, the apertures may be in the shapeof a boat, as described in, for example, U.S. Pat. No. 7,198,836, whichis incorporated herein by reference.

The apertured distal or protubered ends are called “secondaryapertures,” and may be in the shape of polygons, e.g., squares,hexagons, pentagons, ellipses, circles, ovals, slots, or boats. Thesidewall portion of the apertured protuberance extends from the primaryaperture to the secondary aperture.

The term “nonwoven” means a web comprising a plurality of fibers. Thefibers may be bonded to each other or may be unbonded. The fibers may bestaple fibers or continuous fibers or filaments. The fibers may comprisea single material or may comprise a multitude of materials, either as acombination of different fibers or as a combination of similar fiberswith each comprised of different materials.

As used herein, “nonwoven web” is used in its generic sense to define agenerally planar structure that is relatively flat, flexible and porous,and includes staple fibers or continuous fibers or filaments. Thenonwoven web may be the product of any process for forming the same,such as nonwoven spunbond and melt blown nonwoven webs. The nonwoven webmay include a composite or combination of webs. The nonwoven web maycomprise any polymeric material from which a fiber can be producedand/or may comprise cotton or other natural fibers. In an embodiment,the nonwoven web may be a spunbond material, made of polypropylenefiber. Fibers that comprise different polymers may also be blended. Inan embodiment, the fibers may be so-called bi-component (“bi-co”) fibersthat comprise a core of one material and a sheath of another material.

The term “forming structure” or “screen” as used herein refers to athree-dimensional molding apparatus that comprises indentations used toform protuberances, extended cells or apertures in films, orprotuberances in nonwoven webs. In an embodiment, forming structurescomprise tubular members, having a width and a diameter. In alternativeembodiments, forming structures may comprise belts having a width and alength. The transverse direction is the direction parallel to the widthof the forming structure. The machine direction is the directionparallel to the direction of rotation of the forming structure, and isperpendicular to the transverse direction.

As used herein, the term “activating” or “activation” refers to aprocess of stretching a material beyond a point where its physicalproperties are changed. In the case of a nonwoven web, sufficientactivation of the web will result in the nonwoven web being moreextensible and/or improving its tactile properties. In an activationprocess, forces are applied to a material causing the material tostretch. Polymer films and nonwoven webs may be mechanically activated,for example. Mechanical activation processes comprise the use of amachine or apparatus to apply forces to the web to cause stretching ofthe web to an extent sufficient to cause permanent deformation of theweb. Methods and apparatus used for activating webs of materialsinclude, but are not limited to, activating the web through intermeshinggears or plates, activating the web through incremental stretching,activating the web by ring rolling, activating the web by tenter framestretching, canted wheel stretchers or bow rollers, and activating theweb in the machine direction between nips or roll stacks operating atdifferent speeds to mechanically stretch the components, andcombinations thereof.

Embodiments of the Invention

FIG. 1 schematically illustrates an absorbent article 100 in accordancewith embodiments of the invention. As illustrated, the absorbent article100 includes a topsheet 110, a backsheet 120, and an absorbent core 130positioned in between the topesheet 110 and the backsheet 120. Theabsorbent article 100 also includes a fluid distribution material 140positioned in between the topsheet 110 and the absorbent core 130.

The topsheet 110, which may be in the form of a two-dimensional orthree-dimensional apertured film, a nonwoven web, or a laminate of anapertured film and a nonwoven web, is permeable to fluids and isconfigured to face the user wearing the absorbent article 100 andcontact the user's skin. The topsheet 110 receives insults of fluid fromthe user, and the fluid passes through the topsheet 110 to the fluiddistribution material 140. The fluid distribution material 140,embodiments of which are described in further detail below, is alsopermeable and is configured to receive the fluid from the topsheet 110and distribute the fluid to the absorbent core 130. The absorbent core130, which includes absorbent materials, receives the fluid from thefluid distribution material 140 and stores the fluid until the absorbentarticle 100 is discarded. The backsheet 120, which is impermeable toliquid and may be in the form of a polymer film or laminate of a polymerfilm and nonwoven web, prevents liquid and other body exudates fromleaking out of the bottom side of the absorbent core 130. The backsheet120 may be breathable so that air, but not liquid, may pass through.

In an embodiment, the topsheet 110 and the fluid distribution material140 may be integrally formed as a fluid management system 150. Forexample, the topsheet 110 and the fluid distribution material 140 may bein a face to face relationship and attached to each other at theirperipheries, or may be attached to each other at a plurality oflocations, or continuously, across the webs to form a composite web.Such attachment may be achieved with one or more adhesives, or bythermal bonding, or by ultrasonic bonding, or by any other attachmentmeans known in the art. In an embodiment, the absorbent article 100 maynot include a topsheet 110. If so, the fluid distribution material 140may function by itself as the fluid management system and be configuredto be in contact with the user wearing the absorbent article 100.

FIG. 2 schematically illustrates a cross-section of a fluid distributionmaterial 200, which may be used as the fluid distribution material 140of FIG. 1, in accordance with embodiments of the invention. Asillustrated, the fluid distribution material 200 includes a formed filmlayer 210 and a nonwoven layer 230. The formed film layer 210 has afirst side 212 and a second side 214 that is opposite the first side212. The formed film layer 210 includes a plurality of aperturedprotuberances 216. Each of the apertured protuberances 216 includes acontinuous sidewall 218 extending from the first side 212 of the formedfilm layer 210 to a distal end 220 that includes a secondary aperture222, as illustrated. The first side 212 of the formed film layer 210also includes land areas 224 in between the apertured protuberances 216.

The second side 214 of the formed film layer 210 has a plurality ofprimary apertures 226 aligned with the plurality of protuberances 216.As such, the primary apertures 226 in the second side 214 of the formedfilm layer 210 are also considered to be proximal apertures 226 of theapertured protuberances 216, while the secondary apertures 222 at thedistal ends 220 of the apertured protuberances 216 may also beconsidered to be distal apertures 222 of the apertured protuberances216. The second side 214 of the formed film layer 210 also includes landareas 228 in between the proximal apertures 226.

In an embodiment, the apertured protuberances 216 may be arranged in apattern having about 10 to about 40 protuberances per linear inch or“mesh,” i.e., about 10 mesh to about 40 mesh. The pattern may be ahexagonal pattern, a square pattern, a staggered pattern, or any othertype of pattern or design. In an embodiment, the apertured protuberances216 may be arranged in a 10-25 mesh pattern. In an embodiment, theapertured protuberances 216 may be arranged in about an 11 mesh pattern.In an embodiment, the apertured protuberances 216 may be arranged inabout a 22 mesh pattern. In an embodiment, the apertured protuberances216 may be arranged in a 40 mesh pattern. In an embodiment, the proximalapertures 226 may be hexagonal in shape and have approximately the samesize. In an embodiment, the proximal apertures 226 may have differentsizes and/or shapes, as described in further detail below.

The polymer of the formed film layer 210 may include one or morepolyolefins, including but not limited to polyethylene, ultra-lowdensity polyethylene, low density polyethylene, linear low densitypolyethylene, linear medium density polyethylene, high densitypolyethylene, polypropylene, ethylene-vinyl acetates, metallocene, aswell as other polymers. Other polymers include but are not limited toelastomeric polymers, including but not limited to polypropylene basedelastomers, ethylene based elastomers, copolyester based elastomers,olefin block copolymers, styrenic block copolymers and the like, orcombinations thereof. Additives, such as surfactants, fillers,colorants, opacifying agents and/or other additives known in the art mayalso be used in the formed film layer 210.

Returning to FIG. 2, the nonwoven layer 230 has a first side 232 and asecond side 234 opposite the first side 232. In the illustratedembodiment, the first side 232 of the nonwoven layer 230 contacts thesecond side 214 of the formed film layer 210. The nonwoven layer 230includes a plurality of fibers 236.

Nonwoven webs that may be used for the nonwoven layer 230 may be formedfrom many processes, including but not limited to spunbonding processes,melt-blowing processes, hydroentangling processes, spunlacing processes,air-laying, and bonded carded web processes, or combinations thereof, asare known in the nonwoven art. In an embodiment, the nonwoven layer 230may be a spunbonded nonwoven web. In an embodiment, the fibers 236 inthe nonwoven layer 230 may be polypropylene fibers. In an embodiment,the nonwoven layer 230 may include natural fibers, such as cotton.

In an embodiment, the formed film layer 210 is attached to the nonwovenlayer 230 at bond sites 240 where the first side 232 of the nonwovenlayer 230 contacts the land areas 228 of the second surface 214 of theformed film layer 210. In an embodiment, the fibers 236 at the bondsites 240 are embedded into the land areas 228 of the formed film layer210, which may be accomplished by a vacuum formed lamination process, asdescribed in further detail below. The bond sites 240 are contemplatedto be distributed in a pattern, commensurate with some or all of theland areas 228.

FIG. 3 is an enlarged photograph of one side of a fluid distributionmaterial 300 in accordance with an embodiment of the invention, whichmay be used as the fluid distribution material 140 of FIG. 1. Asillustrated, the fluid distribution material 300 includes a formed filmlayer 310 and a nonwoven layer 330 on top of the formed film layer 310.The formed film layer 310 includes apertures 326 and land areas 328extending between the apertures 326. The nonwoven layer 330 includes aplurality of continuous fibers 336 that extend across the land areas 328and the apertures 326 of the formed film layer 310. The continuousfibers 336 are attached to the land areas 328 at bond sites 340.

A closer view of the apertures 326, land areas 328, and bond sites 340is illustrated in FIG. 4.

FIG. 5 is an enlarged photograph of a partial cross-sectional view ofthe fluid distribution material 300 of FIG. 3 with the formed film layer310 on top of the nonwoven layer 330. FIG. 5 also shows a plurality ofapertured protuberances 316 with land areas 324 extending in betweenadjacent apertured protuberances 316. The apertured protuberances 316(FIG. 5) and corresponding apertures 326 (FIGS. 3 and 4) are arranged ina 22 mesh pattern, and each of the apertures 326 has a hexagonal (“hex”)shape, as represented by the dashed white lines in FIG. 4.

FIG. 6 is an enlarged photograph of one side of a fluid distributionmaterial 600 in accordance with an embodiment of the invention, whichmay be used as the fluid distribution material 140 of FIG. 1. Asillustrated, the fluid distribution material 600 includes a formed filmlayer 610 and a nonwoven layer 630 on top of the formed film layer 610.The formed film layer 610 includes three different types of apertures626A, 626B, 626C, and land areas 628 extending between the apertures626A, 626B, 626C. As illustrated, the apertures 626A, 626B, 626C arearranged in a pattern that resembles a blossom or flower, with a center,substantially-round aperture 626A being surrounded by four smaller,substantially-round apertures 626B and four elliptical or oval-shapedapertures 626C, each having their major axis extending at approximately45 degree angles relative to an x-y grid. The circular apertures 626A,626B may have a mesh count of about 15 apertures per linear inch (i.e.,15 mesh) in the x direction and they direction. The nonwoven layer 630includes a plurality of continuous fibers 636 that extend across theland areas 628 and the apertures 626A, 626B, 626C of the formed filmlayer 610. The continuous fibers 636 are attached to the land areas 628at bond sites 640.

A closer view of the apertures 626B, 626C, land areas 628, and bondsites 640 is illustrated in FIG. 7.

FIG. 8 is an enlarged photograph of a partial cross-sectional view ofthe fluid distribution material 600 of FIG. 6 with the formed film layer610 on top of the nonwoven layer 630. FIG. 6 also shows a plurality ofapertured protuberances 616 with land areas 624 extending in betweenadjacent apertured protuberances 616.

FIG. 9 schematically illustrates an apparatus 900 that may be used tomanufacture the fluid distribution materials of embodiments of theinvention described herein. As illustrated, an extrusion die 902extrudes polymer melt curtain 904 onto a forming structure 906 thatrotates about a cylinder 908 that has a vacuum slot 910 through which avacuum is pulled. The polymer melt curtain 904 may include, for example,one or more polyolefin materials and a surfactant, as well as one ormore additives, such as a colorant. A nonwoven web 912 is unwound from aroll 914 over a laminating roller 916 and directed to the melt curtain904 while the melt curtain 904 is still molten at an impingement point918 between the rotating forming structure 906 and the laminating roller916.

The fibers of the nonwoven web 912 adjacent to the melt curtain 904embed in the surface of the melt curtain 904 as the two layers crossover the vacuum slot 910 together, where the apertured protuberances areformed in the polymer web (i.e., the solidified melt curtain 904) insubstantially the same pattern that is provided by the forming structure906. As the polymer web (which solidifies to form, for example, theformed film layer 210 of FIG. 2) is apertured, air flow is initiatedthrough the apertured protuberances (e.g., 216) which cools andsolidifies the apertured protuberances (e.g., 216). The polymer web isalso cooled by the forming structure 906 as the fibers (e.g., 236) ofthe nonwoven are embedded in the land areas (e.g., 228) between theapertured protuberances (e.g., 216) so that the nonwoven is bonded tothe formed film layer (e.g., 210) at the land areas (e.g., 228). Theresulting vacuum formed laminate 920 is pulled off of forming structure906 by a peel roller 922 and travels to one or more subsequent rollers924 until it may be wound by a winder 930 into a roll 932. Additionalrollers and/or other pieces of equipment may be used in the apparatus900.

The illustrated embodiment is not intended to be limiting in any way.For example, in an embodiment, the apparatus 900 may also includeadditional equipment, such as intermeshing gears that may be used toactivate the fluid distribution material in the machine direction or thetransverse direction, if desired. Other equipment that may be includedin the apparatus 900 include, but are not limited to, corona treatmentapparatus, printers, festooning equipment, spooling equipment, andadditional processing equipment that may emboss or provide additionalapertures to the vacuum formed laminate 920.

FIGS. 10-13 schematically illustrate how the fluid distribution material200 handles a fluid insult 1000 and distributes the fluid insult 1000 toa substrate 240 located beneath the fluid distribution material 200,which may be an absorbent core, as described above, or may be a blotterpaper used during testing, as described below. Although a topsheet maybe positioned above the fluid distribution material 200, as describedabove, a topsheet is not illustrated in FIGS. 10-13 for simplicity.

As illustrated in FIG. 10, the fluid insult 1000, which is schematicallyrepresented as a plurality of droplets, is introduced to the formed filmlayer 210 side of the fluid distribution material 200. FIG. 11illustrates the initial phase of fluid strikethrough. Portions of theinsult 1000 are able to enter the unobstructed apertured protuberances216 and pass through to the nonwoven layer 230, while other portions ofthe insult 100 are trapped on the land areas 224 between the aperturedprotuberances 216. As the initial fluid that entered the aperturedprotuberances 216 drains into and spreads along the nonwoven layer 230,and even passes through to the substrate 240 below, the fluid in betweenthe apertured protuberances 216 is siphoned into the aperturedprotuberances 216, due to the surface tension of the fluid and thehydrophilic nature of the formed film layer 210, until all orsubstantially all of the fluid passes through the formed film layer 210of the fluid distribution material 200, as illustrated in FIGS. 12 and13. Although it is desirable to have the nonwoven layer 230 to also behydrophilic, the nonwoven layer 230 may in some embodiments behydrophobic.

EXAMPLES

A series of fluid distribution materials were created using theapparatus 900 described above. A hydrophilic spunbond nonwoven,manufactured by Fitesa of Simpsonville, S.C., comprising a plurality ofpolypropylene fibers and having a nominal basis weight of 12 grams persquare meter (gsm) was used as the nonwoven web 912. A blend of lowdensity polyethylene, high density polyethylene, titanium dioxide andsurfactant was extruded through the extrusion die 902 to create the meltcurtain 904, which was cast onto different forming structures 906 as thenonwoven web 912 was fed into the impingement point 918 to createlaminates 920 with formed film layers having different patterns ofapertured protuberances and open areas. The formed film layers had abasis weight of about 18 gsm so that the laminates 920 had a total basisweight of about 30 gsm.

The open area, which is the percent area of the openings through thesample as compared to the total area of the sample, for each sample wasmeasured using a computerized video device that includes a video camera,a microscope using a 24× magnification, and imaging software thatmeasures contrast. A magnified image was taken of the sample whenlooking at the formed film layer side of the sample, and the videocamera, which can discern the openings through the sample from solidportions of the sample via contrast, digitized the data to calculate thepercent open area. Table I summarizes the laminated (“laminate”) samplesthat were created, along with the respective open areas that weremeasured.

TABLE I Fluid Distribution Material (Laminate) Samples Formed Film LayerApertured “Laminate” Protuberance Open Area Sample Pattern (%) 1 11 meshhexagonal 5.4 2 22 mesh hexagonal 5.5 3 40 mesh hexagonal 6.3 4 15 meshblossom 6.8

FIGS. 3-5 (described above) illustrate a portion of Sample 2 and FIGS.6-8 (described above) illustrate a portion of Sample 4. As noted above,“mesh” refers to the number of apertures per linear inch, “hexagonal”refers to the shape of the apertures, and “blossom” refers to thepattern illustrated in FIG. 9 that has different sized and shapedapertures that are arranged in a blossom or flower pattern.

The same blend of materials and forming structures that were used tocreate the formed film layers for Samples 1-4 were used to create onlyapertured formed films having a basis weight of about 18 gsm, which isthe same basis weight of the formed film layers of Samples 1-4. The openarea for each film (absent the nonwoven web 912) was measured under amicroscope using a 24× magnification and imaging software that measurescontrast. Each of the film samples was placed on top of (but not bondedin any way to) the same spunbond nonwoven web 912 that was used tocreate the laminates for Samples 1-4 (i.e., a 12 gsm spunbondpolypropylene nonwoven web manufactured by Fitesa of Simpsonville,S.C.), with the apertured protuberances extending in a direction awayfrom the nonwoven web to form “stacks” of formed films and nonwovenwebs. Table II summarizes the comparative stack (“stack”) samples thatwere created, along with the respective open areas that were measured inthe same manner as the open areas of the laminate samples, with theformed film side of the stack facing the video camera.

TABLE II Comparative Formed Film/Nonwoven “Stack” Samples Formed FilmApertured “Stack” Protuberance Sample Pattern Open Area (%) 5 11 meshhexagonal 1.4% 6 22 mesh hexagonal 2.6% 7 40 mesh hexagonal 2.4% 8 15mesh blossom 2.1%

Each of the stack samples had an open area lower than the open area of alaminate sample having the same apertured protuberance pattern, whichindicates that the fibers in the nonwoven layers of the laminate samplesmay have spread apart at the locations of the apertured protuberances toprovide a higher open area. Without being bound by theory (and returningto FIG. 2), it is postulated that during the vacuum forming laminationprocess, air being pulled through the nonwoven layer 230 and the formedfilm layer 210 may cause the fibers 236 located adjacent the proximalapertures 226 to separate and gather at a higher density at the landareas 228 where there is no air flow as the polymer in the formed filmlayer 210 cools on the forming structure. When the polymer in the formedfilm layer 210 solidifies, the fibers 236 of the nonwoven layer 230 areessentially locked in place at the bond sites 240 while the fibers 236located adjacent the proximal apertures 226 remain spread apart.

Strikethrough Time and Rewet Testing

All samples were tested for suitability for use as a fluid distributionmaterial in accordance with embodiments of the invention. Specifically,for each sample, strikethrough time and rewet, which is a measure ofdryness, were determined for three different test specimens by a “ListerAC” fluid testing device, by Lenzing Technik GmbH & Co KG, Austria. Theprocedures for measuring strikethrough time (“Strikethrough TestMethod”) and rewet (“Rewet Test Method”), which are based on theprinciples outlined in EDANA test methods ERT 150.5-02 and ERT 151.3-02,respectively, will now be described. All of the test specimens andabsorbent substrates, filter papers and pickup papers described belowwere conditioned at 23° C.±2° C. at 50%±5% relative humidity for 24hours.

For the Strikethrough Test Method, each test specimen was cut into a5″×5″ (125 mm×125 mm) piece and placed over an absorbent substrate inthe form of a stack of three (3) pieces of 4″×4″ filter (blotter) paper.The test specimen was oriented so that the formed film layer facedupward and the nonwoven layer was in contact with the filter paper. A500 g strikethrough plate with a 100 mm×100 mm base dimension and anorifice with electrodes extending into the orifice was placed on top ofthe test specimen. A 5 mL sample of fluid that simulates urine andconsists of a solution of 9.0 g/l of analytical grade sodium chloride indeionized water, with a surface tension of 70±2 mN/m at 23±2° C., wasdispersed into the orifice from a height of 30 mm above the surface ofthe test specimen. The fluid completed a circuit with the electrodes,which started a timer. When the fluid was completely struck through theorifice, the circuit was broken and the timer stopped, therebyregistering the elapsed time or “strikethrough time” in seconds.

For the “Rewet Test Method,” after the initial insult from theStrikethrough Test Method, an additional insult was dispensed to thecenter of the test specimen with the strikethrough plate still in place.The additional insult was based on the total insult (including theinitial 5 mL insult from the Strikethrough Test Method) needed to fullysaturate the underlying absorbent substrate and was calculated bymultiplying the weight of the stack of three pieces of filter paper(when dry) by the load factor of the filter paper, and was determined tobe 10 mL. The strikethrough plate was removed and a 4000 g rewet weightwith a 100 mm×100 mm footing was placed on top of the test specimen toallow the fluid to thoroughly spread out into the absorbent substrate.Two pre-weighed 5″×5″ pick up (blotter) papers were pressed against thesurface of the test specimen with the rewet weight to create a pressureof about 0.50 psi, to simulate a toddler sitting on a diaper, for anadditional two minutes. The wetted pickup papers were weighed. Anyresidual wetness in the test specimen is transferred to the pickuppapers, and the difference between the pre-measured dry weight of thepickup papers and the wetted weight of the pickup papers is the “rewetvalue” in grams. The average strikethrough time and rewet value testresults for three test specimens for each sample are listed in below inTable III.

TABLE III Strikethrough Time and Rewet Test Results Strikethrough TimeRewet Value Sample Description (seconds) (grams) 1 11 mesh hexagonal0.97 0.060 laminate 2 22 mesh hexagonal 1.47 0.052 laminate 3 40 meshhexagonal 2.26 0.074 laminate 4 15 mesh blossom 1.52 0.059 laminate 5 11mesh hexagonal 0.98 0.104 stack 6 22 mesh hexagonal 1.57 0.076 stack 740 mesh hexagonal 2.54 0.158 stack 8 15 mesh blossom 1.36 0.107 stack

The strikethrough time and rewet results are also plotted in FIGS. 14and 15, respectively. As shown in FIG. 14, all of the laminate sampleswith hexagonal shaped apertures (“hex”) had faster strikethrough timesas compared to their corresponding stack samples. The laminate samplewith the blossom pattern (Sample 4) had a slightly slower strikethroughtime than its corresponding stack sample (Sample 8). As shown in FIG.15, all of the laminate samples (Samples 1-4) had at least 30% lowerrewet values than their corresponding stack samples (Samples 5-8), andeach of the laminate samples (Samples 1-4) had rewet values of less than0.075, while each of the stack samples (Samples 5-8) had rewet valuesgreater than 0.075.

Compressibility Testing

All samples were also tested for thickness when under pressure so thatthe compressibility of the samples could be determined. Thicknesses weremeasured using a Testing Machines, Inc. Model 49-70 motorized low-loadmicrometer with an anvil having a diameter of 2 inches, a dead weightload of 298 grams (0.657 pounds), which is equivalent to an appliedpressure of 0.21 psi, and a dwell time of 2-5 seconds. Multiplemeasurements were made for each sample at different locations across thesample, and the measurements for each sample were averaged to determinea baseline thickness measurement for each sample. Additional weight wasadded to the anvil to increase the applied pressure to 0.31 psi, 0.40psi, 0.50 psi and 0.60 psi. 0.50 psi is commonly likened to the pressureexerted by a toddler sitting on a diaper. Multiple measurements weremade for each sample at different locations across the sample at eachpressure, and the measurements for each sample at each pressure wereaveraged. The results of the thickness testing under different appliedpressures are listed in Table IV below.

TABLE IV Thickness Under Applied Pressure Test Results ThicknessThickness Thickness Thickness Thickness (microns) (microns) (microns)(microns) (microns) @ @ @ Sample @ 0.21 psi @ 0.31 psi 0.40 psi 0.50 psi0.60 psi 1 756 728 710 698 686 2 530 513 500 491 485 3 382 375 360 353353 4 635 625 614 604 592 5 730 689 667 642 608 6 567 553 543 523 516 7417 409 394 386 375 8 683 656 638 623 609

The results of the thickness testing under different pressures were usedto calculate the compressibility of the samples a various pressures,using the thickness measurement at the lowest pressure (i.e., 0.21 psi)as the baseline. The compressibility of each sample was calculated foreach of the 0.31 psi, 0.40 psi, 0.50 psi, and 0.60 psi applied pressuresusing the following equation (1):

$\begin{matrix}{{{compressibility}\mspace{14mu}(\%)} = {\frac{\left( {{thickness}_{x\mspace{14mu}{psi}} - {thickness}_{0.21\mspace{14mu}{psi}}} \right)}{{thickness}_{0.21\mspace{14mu}{psi}}} \times 100}} & (1)\end{matrix}$where x is the applied pressure, thickness_(x psi) is the averagethickness at the applied pressure, and thickness_(0.21 psi) is theaverage thickness at 0.21 psi applied pressure. The results are listedin the following Table V.

TABLE V Compressibility Test Results Compressibility CompressibilityCompressibility Compressibility Sam- (%) (%) (%) (%) ple @ 0.31 psi @0.40 psi @ 0.50 psi @ 0.60 psi 1 3.7 6.1 7.7 9.3 2 3.2 5.7 7.4 8.5 3 1.85.8 7.6 7.6 4 1.6 3.3 4.9 6.8 5 5.6 8.6 12.1 16.7 6 2.5 4.2 7.8 9.0 71.9 5.5 7.4 10.1 8 4.0 6.6 8.8 10.8

The compressibility test results are also illustrated in FIGS. 16-19,with the baseline applied pressure (i.e. 0.21 psi) set to 0% for allsamples. Specifically, FIG. 16 illustrates the results for Sample 1(laminate) and Sample 5 (stack), which each had a formed film layer withapertured protuberances in the 11 mesh hexagonal (“hex”) pattern. FIG.17 illustrates the results for Sample 2 (laminate) and Sample 6 (stack),which each had a formed film layer with apertured protuberances in the22 mesh hexagonal (“hex”) pattern. FIG. 18 illustrates the results forSample 3 (laminate) and Sample 7 (stack), which each had a formed filmlayer with apertured protuberances in the 40 mesh hexagonal (“hex”)pattern. FIG. 19 illustrates the results for Sample 4 (laminate) andSample 8 (stack), which each had a formed film layer with aperturedprotuberances in the 15 mesh blossom pattern.

Linear trendlines were generated for each set of data and included inthe Figures. Table VI lists the slopes, intercepts, and R² values forthe associated trendline for each sample.

TABLE VI Summary of Linear Trendline Data from FIGS. 16-19 Sample SlopeIntercept R² 1 23.27 −4.04 0.96 2 21.81 −3.85 0.96 3 21.53 −4.14 0.90 417.42 −3.72 1.00 5 41.16 −8.03 0.99 6 24.02 −5.01 0.98 7 26.45 −5.710.99 8 27.19 −4.95 0.98

FIGS. 16-19 and the linear trendlines indicate that for each of theapertured protuberance patterns, the laminates tend to have flatterslopes than the stacks, which provides an indication that the laminatesdo not compress as much as the stacks as the applied pressure isincreased, especially for the 11 mesh hexagonal and 15 mesh blossompatterns. Without being bound by theory, it is postulated that for thelaminates, the fibers of the nonwoven that are embedded in the lands ofthe apertured formed film provide a scaffolding structure that allowsthe apertured protuberances to better maintain their shape and notcompress as much as apertured protuberances that do not have such abenefit. Such a benefit may provide a particular advantage so that thefluid distribution material performs well under the applied pressuresexperienced while being worn by a user.

Embodiments of the invention provide a fluid distribution material thatreduces residual wetness, even after the absorbent article is subjectedto pressure. The combination of the formed film layer, which has a lowerbasis weight compared to known film-only acquisition distributionmaterials, and the nonwoven layer laminated to the formed film layer mayprovide a modulus that is sufficient to allow the fluid distributionmaterial to be converted into an absorbent article, as desired.

The embodiments described herein represent a number of possibleimplementations and examples and are not intended to necessarily limitthe present disclosure to any specific embodiments. Instead, variousmodifications can be made to these embodiments, and differentcombinations of various embodiments described herein may be used as partof the invention, even if not expressly described, as would beunderstood by one of ordinary skill in the art. Any such modificationsare intended to be included within the spirit and scope of the presentdisclosure and protected by the following claims.

For example, even though the testing was completed with the fluiddistribution layer being oriented so that the insult contacted theformed film layer first, it is contemplated that in some embodiments,the fluid distribution layer may be used in an absorbent article withthe nonwoven layer facing the topsheet and the formed film layer facingthe absorbent core. The above-described and illustrated embodiments arenot intended to be limiting in any way.

What is claimed is:
 1. A fluid distribution material for use in anabsorbent article, the fluid distribution material comprising: a formedfilm layer having a user-facing side and a garment-facing side oppositethe user-facing side, the formed film layer comprising a plurality ofapertured protuberances arranged in a pattern having 10 to 40protuberances per linear inch, each of the protuberances comprising acontinuous sidewall extending from the user-facing side, thegarment-facing side having a plurality of apertures aligned with theplurality of apertured protuberances and land areas in between theapertures; and a nonwoven layer laminated to the garment-facing side ofthe formed film layer, the nonwoven layer comprising a plurality ofcontinuous fibers extending across the land areas and the plurality ofapertures of the formed film layer and attached to the land areas atbond sites, wherein the fluid distribution material has acompressibility of less than 10% between pressures of 0.21 psi and 0.60psi, and wherein the plurality of continuous fibers of the nonwovenlayer are embedded into the land areas of the formed film layer at thebond sites.
 2. The fluid distribution material according to claim 1,wherein the formed film layer has a basis weight of between about 10 gsmand about 25 gsm.
 3. The fluid distribution material according to claim1, wherein the nonwoven layer has a basis weight of between about 10 gsmand about 15 gsm.
 4. The fluid distribution material according to claim1, wherein the nonwoven layer comprises a spunbond nonwoven.
 5. A fluidmanagement system for use in an absorbent article, the fluid managementsystem comprising: a fluid distribution material comprising a formedfilm layer having a user-facing side and a garment-facing side oppositethe user-facing side, the formed film layer comprising a plurality ofapertured protuberances arranged in a pattern having 10 to 40protuberances per linear inch, each of the protuberances comprising acontinuous sidewall extending from the user-facing side, thegarment-facing side having a plurality of apertures aligned with theplurality of apertured protuberances and land areas in between theapertures; and a nonwoven layer laminated to the garment-facing side ofthe formed film layer, the nonwoven layer comprising a plurality ofcontinuous fibers extending across the land areas and the plurality ofapertures of the formed film layer and attached to the land areas atbond sites, wherein the fluid distribution material has acompressibility of less than 10% between pressures of 0.21 psi and 0.60psi, and wherein the plurality of continuous fibers of the nonwovenlayer are embedded into the land areas of the formed film layer at thebond sites; and a topsheet attached to the fluid distribution material,wherein the user-facing side of the formed film layer faces thetopsheet.
 6. The fluid management system according to claim 5, whereinthe formed film layer has a basis weight of between about 10 gsm andabout 25 gsm.
 7. The fluid management system according to claim 5,wherein the nonwoven layer has a basis weight of between about 10 gsmand about 15 gsm.
 8. The fluid management system according to claim 5,wherein the topsheet comprises an apertured formed film.
 9. The fluidmanagement system according to claim 5, wherein the topsheet comprises anonwoven web.
 10. The fluid management system according to claim 5,wherein the topsheet comprises a laminate.
 11. An absorbent articlecomprising: a fluid distribution material, the fluid distributionmaterial comprising a formed film layer having a user-facing side and agarment-facing side opposite the user-facing side, the formed film layercomprising a plurality of apertured protuberances arranged in a patternhaving 10 to 40 protuberances per linear inch, each of the protuberancescomprising a continuous sidewall extending from the user-facing side,the garment-facing side having a plurality of apertures aligned with theplurality of apertured protuberances and land areas in between theapertures; and a nonwoven layer laminated to the garment-facing side ofthe formed film layer, the nonwoven layer comprising a plurality ofcontinuous fibers extending across the land areas and the plurality ofapertures of the formed film layer and attached to the land areas atbond sites, wherein the fluid distribution material has acompressibility of less than 10% between pressures of 0.21 psi and 0.60psi, and wherein the plurality of continuous fibers of the nonwovenlayer are embedded into the land areas of the formed film layer at thebond sites; a backsheet; and an absorbent material in between the fluiddistribution material and the backsheet.
 12. The absorbent articleaccording to claim 11, wherein the formed film layer has a basis weightof between about 10 gsm and about 25 gsm.
 13. The absorbent articleaccording to claim 11, wherein the nonwoven layer has a basis weight ofbetween about 10 gsm and about 15 gsm.
 14. The absorbent articleaccording to claim 11, further comprising a topsheet, wherein the fluiddistribution material is disposed between topsheet and the absorbentcore.
 15. The absorbent article according to claim 14, wherein thetopsheet comprises an apertured formed film.
 16. The absorbent articleaccording to claim 14, wherein the topsheet comprises a nonwoven web.17. The absorbent article according to claim 14, wherein the topsheetcomprises a laminate.